JP3132889B2 - Pressure-sensitive recording sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure-sensitive material in which microcapsules containing at least one of a color former and a developer are individually laminated or mixed and applied to one surface of a support. Recording layer, polyolefin resin laminate layer, silicone compound with one or more functional groups of acryloyl group, methacryloyl group, epoxy group introduced into terminal or side chain of molecular main chain of polydialkylcyclohexane from ultraviolet rays or electron beam The present invention relates to a pressure-sensitive recording sheet provided with a silicone resin layer, an adhesive layer, and an opaque covering sheet sequentially cured by at least one kind of high energy rays. This pressure-sensitive recording sheet has the property that the recording is not exposed and the releasability,
It has water resistance, chemical resistance, oil resistance, scratch resistance, and dust generation suppression. Therefore, it can be used as labels, slips, correspondence, entertainment items, and clean room recording paper.

[0002]

2. Description of the Related Art The pressure-sensitive recording layer used in the present invention is a self-coloring pressure-sensitive recording type, which has been developed from a so-called carbonless copying paper. Also called paper. The composition consists of a step of applying a coating of microcapsules containing a colorless dye (hereinafter referred to as a color forming agent) to a support, and an electron-accepting material such as acid clay, a phenol resin, and an organic acidic substance on the coating. A production method by two-layer coating (including a method in which the order of application is reversed) consisting of two steps and a step of applying a substance (hereinafter referred to as a color developer), or the above two components, or any one of the components. Manufacturing method by microencapsulation, uniform mixing and one layer coating
No. 7-16096). In such a self-coloring pressure-sensitive recording sheet, since a color former and a developer are present in the vicinity, a printed image with a high color density is easily obtained, but unintentional unintended undesired due to friction during production or handling. There is a problem that coloring stains easily occur.

The self-coloring pressure-sensitive recording sheet is destined to satisfy both the practically necessary coloring performance and the suppression of unnecessary coloring stains under the conditions in which it is used. Efforts are being made to satisfy both conflicting properties of dirt. Further, such self-coloring pressure-sensitive recording sheets are often used for attaching continuous slips to luggage or as backing paper, and therefore, simultaneously have water resistance, oil resistance, stain resistance, recording properties, and the like. It was extremely difficult to meet these requirements simultaneously. Furthermore, in a continuous slip, if one of them is used for lamination, the lower paper must be release paper, so that it is often used in the lowermost layer of the slip, and the color density is necessarily low. Was something. In such a configuration, a release paper of the same area is necessary. For example, not only is the release paper discharged in the case of performing continuous label sticking remarkably obstructive work, but generally, release paper is generally used. However, there is a problem in disposal because it cannot be regenerated, and in use, there is a problem that the combined thickness of the pressure-sensitive paper and the release paper increases. further,
In the self-coloring type pressure-sensitive recording sheet, the information that is pressure-sensitively recorded is highly open and inevitably exposed to the public.
If you wanted to hide the information, you had to put it in a separate bag.

Heretofore, for example, a method of providing a laminate layer by a vacuum adhesion method on a recording layer of a self-coloring pressure-sensitive recording sheet (Japanese Patent Publication No. 49-10857), or a recording method having a plastic layer by a melt lamination method Sheets (Japanese Utility Model Laid-Open No. 52-149709) and examples of providing a release layer on these protective layers are known. However, in practice, when a protective layer is provided by melt lamination or lamination, unnecessary color stains can be prevented, but these methods basically assume that the pressure-sensitive recording part is exposed. As a result, the problem of non-disclosure of the record could not be solved.

As another method, a method in which a soluble polymer solution is applied on a self-coloring type pressure-sensitive recording layer and dried to form a coating film can form a thin protective layer.
Disruption of the microcapsules causes remarkable color fogging or the resin covers the microcapsules, almost losing the original self-coloring pressure-sensitive recording properties, and lowering both the color density and the color developing speed, which is not satisfactory. .

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a pressure-sensitive recording sheet which does not sacrifice its original color developing property, reduces color fogging due to friction, and at the same time has a water resistance and oil resistance. Another object of the present invention is to provide a pressure-sensitive recording sheet which satisfies the requirements of, for example, contamination resistance and, if necessary, has the non-disclosure of information.

[0007]

Means for Solving the Problems The present inventors have applied on one side of a support a microcapsule containing at least one of a color former and a developer alone or by mixing them. A pressure-sensitive recording layer, a polyolefin resin laminate layer, and a silicone compound having one or more functional groups selected from acryloyl, methacryloyl, and epoxy groups introduced into the terminal or side chain of the molecular main chain of polydialkylcyclohexane are exposed to ultraviolet light. Alternatively, the invention relating to a pressure-sensitive recording sheet provided with a silicone resin layer, an adhesive layer, and an opaque covering sheet sequentially cured by one or more kinds of high energy rays composed of an electron beam has been completed. The silicone resin layer can contain an inorganic pigment.

In the pressure-sensitive recording sheet of the present invention, the silicone resin provided on the recording surface does not seep into the pressure-sensitive recording layer due to the action of the polyolefin resin laminate layer, and the silicone resin having a small amount of silicone resin has surface releasability. High color density can be obtained. The silicone resin itself exhibits high water resistance as well as releasability from the adhesive layer, and the polyolefin resin laminate layer exhibits high oil resistance. Further, when a label composed of an opaque cover sheet and an adhesive layer is used as a label, release paper is unnecessary, so that not only is there a cost advantage, but also unnecessary release of release paper is not required. By having an adhesive layer and an opaque covering sheet on the silicone resin layer, the pressure-sensitive recorded information can be released to the outside and handled without exposure, and by peeling the opaque covering sheet as necessary, You can read the pressure-sensitive information inside.

The details of the present invention will be described below. As the support used in the pressure-sensitive recording sheet of the present invention, and as the opaque covering sheet, general papers such as glassine paper, woodfree paper, art paper, coated paper and cast paper can be used, and wood pulp, synthetic pulp, Raw materials usually used in papermaking, such as fillers, sizing agents, paper strength agents, dyes, etc., can be used as needed. Also, polyethylene,
Polypropylene, polyethylene terephthalate, plastic sheets such as polyamide, and synthetic paper or nonwoven fabric made of these synthetic fibers, or synthetic resin on one side of paper,
Alternatively, laminated paper, metal foil, or metal foil and paper, vapor-deposited paper, an opaque sheet subjected to hologram treatment, a laminated product of a synthetic resin film, mica paper, glass paper, and the like can also be used. These supports can be made opaque with inorganic or organic pigments, inks and printing layers.

The pressure-sensitive recording layer that can be used in the present invention is not particularly limited, and a conventionally known one can be used. For example, a method of microencapsulation, a wall material of a microcapsule, a color former, an oil for dissolving the color former, a color developer, an adhesive, a microcapsule protective agent, and the like. Examples of the microencapsulation method include a coacervation method (U.S. Pat. No. 2,800,458), an interfacial polymerization method (Japanese Patent Publication No. 47-1763, etc.), and an in-situ polymerization method (Japanese Patent Application Laid-Open No. 51-9079, etc.). Can be used.

As the wall material of the microcapsules, polyurethane, polyurea, epoxy resin, urea / formalin resin, melamine / formalin resin and the like can be used.

Examples of the color former include triallylmethane compounds, diarylmethane compounds, xanthene compounds,
There is no particular limitation as long as a thiazine-based compound, a spiropyran-based compound, or the like can be used, as long as it is generally used for a pressure-sensitive recording material or a heat-sensitive recording material.

Examples of oils for dissolving the color former include aromatic synthetic oils such as diarylalkanes, alkylnaphthalenes, alkylated biphenyls and hydrogenated terphenyls, and aliphatic synthetic oils such as kerosene, naphtha, paraffin oil and chlorinated paraffin. Vegetable oils such as oil, cottonseed oil, soybean oil, and linseed oil can be used.

As a protective agent for the microcapsules, cellulose powder, starch particles, talc, calcined kaolin, calcium carbonate and the like can be used.

Examples of the color developer include clays (eg, acid clay, attapulgite, etc.), organic acids (eg, aromatic carboxy compounds such as salicylic acid, and metal salts thereof), mixtures of organic acids and metal compounds, An acidic polymer (for example, a phenol-formaldehyde resin, a salicylic acid resin, or a metal salt thereof) or the like can be used.

In the present invention, the binder used for forming the pressure-sensitive recording layer includes starches, cellulose derivatives such as hydroxyethylcellulose, methylcellulose, ethylcellulose and carboxymethylcellulose; proteins such as casein and gelatin; starch oxide; and ester compounds. Aqueous natural polymer compounds such as saccharose such as starch, polyvinyl alcohol, modified polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic acid, sodium polyacrylate, acrylamide / acrylate copolymer, acrylamide / acrylate / Methacrylic acid terpolymer, styrene /
Water-soluble synthetic polymer compounds such as alkali salts of maleic anhydride copolymers, latex, polyacrylamide, styrene / maleic anhydride copolymers and latexes, and water-soluble compounds such as alkali salts of ethylene / maleic anhydride copolymers. Adhesive, polyvinyl acetate, polyurethane, polyacrylate, styrene / butadiene copolymer, acrylonitrile / butadiene copolymer, methyl acrylate /
Butadiene copolymer, acrylonitrile / butadiene /
Latexes such as an acrylic acid copolymer and an ethylene / vinyl acetate copolymer are exemplified.

The pigment used in the pressure-sensitive recording layer, polyolefin resin laminate layer or silicone resin layer includes diatomaceous earth, talc, kaolin, calcined kaolin, calcium carbonate, magnesium carbonate, titanium oxide, zinc oxide, Examples include silicon, aluminum hydroxide, and urea-formalin resin.

In addition, zinc stearate as an auxiliary agent,
Higher fatty acid metal salts such as calcium stearate, waxes such as paraffin, paraffin oxide, polyethylene, polyethylene oxide, stearic acid amide, caster wax, etc., dispersants such as sodium dioctyl sulfosuccinate, sulfonic acid-modified polyvinyl alcohol, benzophenone, A benzotriazole-based ultraviolet absorber, a surfactant, a fluorescent dye, and the like are added as necessary.

In the pressure-sensitive recording sheet of the present invention, the pressure-sensitive recording layer may be formed by a blade coating method, an air knife coating method, a gravure coating method, a roll coating coating method, or the like.
Known coating methods such as a bar coating method and a falling curtain coating method can be used. The pressure-sensitive recording layer is preferably subjected to a smoothing treatment.

Further, in the field of pressure-sensitive recording material production, a back coat is applied to prevent curling, a conductive treatment is applied to prevent jamming, and an undercoat layer is provided between the support and the pressure-sensitive recording layer. Various known techniques can be added as necessary.

According to the constitution of the present invention, in order to obtain a high color density, calcium carbonate, talc, silica, clay, barium sulfate, magnesium carbonate, magnesium silicate, and the like are provided between the support and the pressure-sensitive recording layer. Inorganic pigments such as lead sulfate, lead white, zinc white, zinc sulfide, satin white, titanium oxide, antimony oxide, mica, bentonite, calcium silicate, gypsum, aluminum hydroxide, or polystyrene, polyvinyl toluene, styrene / divinyl benzene Providing an undercoat layer containing a finely divided organic pigment such as a polymer, polymethyl methacrylate, a urea / formaldehyde polymer, or polyethylene can be used without any problem.

In the laminate layer made of a polyolefin resin provided on the pressure-sensitive recording layer, the polyolefin resin mentioned here includes, for example, the following substances.
As polyolefin resin, as polyethylene, high-density polyethylene, low-density polyethylene, medium-density polyethylene, linear low-density polyethylene, ultra-high-molecular-weight polyethylene, polypropylene, isotactic, atactic, mixtures thereof, random copolymers with ethylene Alternatively, there is no particular limitation on poly-3-methylpentene-1 such as a block copolymer, but low-density polyethylene and a mixed resin of these polyolefin resins are advantageously used. When providing the polyolefin resin laminate layer or providing the silicone resin, any surface treatment such as corona treatment, flame treatment, and ozone treatment may be used.

If necessary, an aqueous intermediate layer for improving adhesiveness can be provided between the pressure-sensitive recording layer and the polyolefin resin laminate layer. Examples of the resin used for the aqueous intermediate layer mentioned here include the following substances. As natural and semi-synthetic polymers, starch, oxidized starch, etherified starch, dialdehyded starch,
Modified starch compounds such as esterified starch, alginic acid compounds such as sodium alginate and propylene glycol alginate, casein, gelatin, pullulan, dextran, chitin, chitosan, rubber latex, gum arabic, fungi, natural gum, dextrin,
Modified cellulose compounds such as methylcellulose, ethylcellulose, hydroxycellulose and carboxymethylcellulose are exemplified. Synthetic polymers include fully or partially saponified polyvinyl alcohol, acetoacetylated polyvinyl alcohol, esterified product of polyvinyl alcohol and polyvalent carboxylic acid, carboxy-modified polyvinyl alcohol, sulfonic acid-modified polyvinyl alcohol, and olefin-modified Polyvinyl alcohol, nitrile-modified polyvinyl alcohol, amide-modified polyvinyl alcohol, modified polyvinyl alcohol compounds such as pyrrolidone-modified polyvinyl alcohol,
Polyethylene glycol, polyacrylamide, polyacrylic acid, polyacrylic acid compounds such as ammonium polyacrylate, sodium polyacrylate, polyvinylpyrrolidone, polyethyleneimine, polyvinyl ether,
Examples include a polymaleic acid copolymer, polyacrylamide, and a water-soluble alkyd resin. Although not an aqueous polymer in a strict sense, synthetic polymers such as styrene / maleic anhydride copolymer, styrene / butadiene copolymer, butadiene / methacrylate copolymer, acrylonitrile / butadiene / acrylate latex, etc. Can be used in place of the aqueous polymer solution. As the aqueous polymer, the above-mentioned polymers can be used alone or as a mixture to form an aqueous solution, and if necessary, an antifoaming agent, a dispersant, and the like can be used in combination.

The silicone resin release agent for forming the silicone resin layer used in the present invention may be a silicone resin (mainly polydimethylsiloxane) or a solution thereof.
It is an aqueous emulsion, preferably a silicone resin that is cured by heating, ultraviolet light or electron beam,
In addition, various silicone compounds having the same function, fluorine compounds, compounds containing a long-chain alkyl group, and the like can be used. The ultraviolet or electron beam curable silicone resin is a resin in which an acryloyl group or a methacryloyl group is introduced into a terminal or a side chain of a molecular main chain of a general silicone resin, and is a silicone-containing acrylate, a silicone-containing methacrylate or a derivative thereof. . Product names are FM0711, FM0721, FM0725, PS58
3 (above, Chisso Corporation), KP-600, X-62-
7100, X-62-7112, X-62-7140,
X-62-7144, X-62-7153, X-62-
7157, X-62-7158, KNS-5200, X
-62-7166, X-62-7168, X-62-7
177, X-62-7180, X-62-7181, X
-62-7192, X-62-7200, X-62-7
203, X-62-7205, X-62-7931 (above, Shin-Etsu Chemical Co., Ltd.), RC149, RC300, RC
450, RC802, RC710, RC720 (or more,
Goldschmidt), EBECRYL350, EB
ECRYL1360 (these are Daicel UCB Co., Ltd.) and the like. Further, acrylates or methacrylates containing a long-chain alkyl group and silicone-modified compounds thereof are also good ultraviolet or electron beam curable release agents. These can be used alone or in combination of two or more. In addition, these silicone resins have the purpose of increasing the surface strength of the silicone resin layer,
Or for the purpose of improving curability, a general ultraviolet curable resin as a curing aid, or an electron beam curable resin,
They can be mixed and used within a range that does not excessively affect the peel strength.

In order to prevent blocking, an organic or inorganic pigment can be added to the resin forming the silicone resin layer. For example, kaolin, calcined kaolin, talc, limestone, diatomaceous earth, calcium carbonate, water Examples include aluminum oxide, magnesium hydroxide, magnesium carbonate, titanium oxide, barium carbonate, urea-formalin resin, and plastic beads such as styrene.

The photoinitiators used in the present invention, particularly when using the ultraviolet curing method, include acetophenones such as di- and trichloroacetophenone, benzophenone, Michler's ketone, benzyl, benzoin, benzoin alkyl ether, benzyldimethyl ketal, There are methylthiuram monosulfide, thioxanthones, azo compounds, and the like, which are selected from the viewpoint of the type of polymerization reaction of the radiation-curable resin, stability, and suitability for an ultraviolet irradiation device. The amount of the photoinitiator to be used is usually O.O. It is in the range of 1-5%. A storage stabilizer such as hydroquinone may be used in combination with the photoinitiator.

As the ultraviolet irradiation device used in the present invention,
For example, there are a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, a metal halide lamp, and the like, and an ozone-less type that generates less ozone. Generally, a plurality of lamps having an output of 30 w / cm or more are used in parallel.

The electron beam irradiation used in the present invention is performed by using an electron beam accelerator having an acceleration voltage of 100 to 1000 KV, more preferably 100 to 300 KV, in view of transmission power and curing power.
It is preferable that the absorbed dose in one pass be 0.5 to 20 Mrad. If the acceleration voltage or the amount of electron beam irradiation is lower than this range, the electron beam transmission power is too low to perform sufficient curing, and if it is higher than this range, not only does the energy efficiency deteriorate, but also the resin, Undesirable effects on quality such as decomposition of additives and reduction in strength of base paper appear.

The electron beam accelerator may be, for example, any of an electron curtain system, a scanning type, a double scanning type, and the like. In the electron beam irradiation step, the overcoat layer can be cured while a surface shape thereof is transferred by closely attaching a synthetic resin film, a metal foil, a metal drum, or the like to the overcoat layer.

When irradiating with an electron beam, if the oxygen concentration is high, the curing of the electron beam-curable resin is hindered.
Replace with an inert gas such as helium or carbon dioxide and reduce the oxygen concentration to 600 ppm or less, preferably 400 ppm.
The irradiation is preferably performed in an atmosphere controlled as follows.

The coating amount of the silicone resin layer and the coating amount of the polyolefin resin laminate layer are not limited, but are desirably thinner in order to avoid a drop in writing pressure, and preferably 0.2 to 10 g / g. m ² or less, more preferably 0.5 to 3 g / m ² or less.
The method of applying the resin for forming the silicone resin layer and the aqueous intermediate layer of the present invention includes gravure roll and transfer roll coater, bar coater, roll coater, air knife coater, U comma coater, AKKU
Coater, smoothing coater, microgravure coater, air knife coater, reverse roll coater, 4 or 5 roll coater, blade coater, dip coater, bar coater, rod coater, kiss coater, gate roll coater, squeeze coater, drop curtain coater, slide Any coater such as a coater and a die coater may be used. For the polyolefin resin laminate layer, a common laminator such as a melt extrusion die, a T die, or a multilayer simultaneous extrusion die can be used. Also, a polyolefin resin laminate layer can be obtained by bonding a polyolefin resin film on a pressure-sensitive recording layer or an aqueous intermediate layer via an adhesive layer.

Examples of the adhesive used in the present invention include acrylic resin, natural and synthetic rubber, styrene / butadiene copolymer, polyvinyl acetate, vinyl acetate / ethylene copolymer, starch, silicone-based compound, glue, casein, Resins such as polyvinyl alcohol, polyurethane, and polyurethane can be used alone or in the form of a solution, an aqueous solution, or an emulsion. As a method for setting these adhesives, any method such as heat drying, hot melt, ultraviolet curing, and electron beam curing may be used. In addition, depending on the amount of the adhesive applied, the drying / curing method, or the type, after preparing the pressure-sensitive recording sheet of the present invention, the opaque cover sheet and the adhesive layer may be peeled off and attached to another substance such as a label. Alternatively, a function of preventing adhesion (against re-adhesion) even if an attempt is made to adhere again to the silicone resin layer once peeled off can be imparted.

In the pressure-sensitive recording sheet according to the present invention,
Character printing or tint block printing can be used on these supports, or on a pressure-sensitive recording layer, a polyolefin resin laminate layer, a cured silicone resin layer, or an opaque cover sheet. Further, in the present invention, in order to improve the adhesiveness and the wettability, the surface may be subjected to a surface treatment such as a corona treatment.

The pressure-sensitive recording sheet of the present invention has a color former layer or a developer layer, a protective coating layer, an adhesive layer, a release layer, a printing layer, a toner receiving layer, and an ink receiving layer on the surface or the back surface. ,
The heat-sensitive recording layer, the writing layer, the magnetic recording layer and the like can be provided alone or simultaneously. The pressure-sensitive recording sheet of the present invention can be used as a series of copy sheets in combination with other pressure-sensitive recording sheets, back carbon copy sheets, adhesive sheets, printing sheets, transparent films, and the like.

[0035]

In the pressure-sensitive recording sheet, the silicone resin does not seep into the pressure-sensitive recording layer due to the function of the polyolefin resin laminate layer, and a high color density can be obtained while maintaining surface releasability. In addition, since there is no need for a release paper, there is a cost advantage, color can be formed at a good recording density at the time of pressure-sensitive recording, gloss, water resistance, chemical resistance, excellent scratch resistance, and an adhesive layer on the release layer, Because of the opaque covering sheet, pressure-sensitive recorded information can be handled without being disclosed and exposed to the outside. After peeling off the adhesive layer and the opaque covering sheet, they can be used as sticking labels.

[0036]

EXAMPLES The present invention will be described in detail below with reference to examples, but the contents of the present invention are not limited to the examples.
All parts and percentages shown below are based on weight. Also,
The value indicating the amount of smear is the amount of smear after drying unless otherwise specified.

Preliminary Operation (Preparation of Self-Coloring Pressure-Sensitive Recording Layer) A microcapsule containing a color-forming agent used for the pressure-sensitive recording layer was prepared as follows. First, 13 parts of crystal violet lactone was heated and dissolved in 90 parts of Hisol SAS N-296 (manufactured by Nippon Petrochemical Co., Ltd.) to obtain an internal phase oil. Melamine 10 parts and 37%
25 parts of formalin were heated together with 100 parts of water to obtain a melamine-formalin initial polycondensate. Then, the internal phase oil was added to a 5% styrene / maleic anhydride copolymer aqueous solution 150.
And the above-mentioned melamine-formalin polycondensate is added to this emulsion, and the liquid temperature is maintained at 70 ° C. for 2 hours to obtain a microcapsule dispersion liquid containing a melamine-formalin resin film and containing a color former. I got The average particle size of the obtained microcapsules was about 6 μm.

A coating for the self-coloring pressure-sensitive recording layer was prepared according to the following formulation. The unit is parts by dry weight. Microcapsules containing color former 110 parts Developer (PR26298 manufactured by Sumitomo Durez Co., Ltd.) 65 parts Starch particles 290 parts Kaolin clay 70 parts Oxidized starch 100 parts

The self-coloring pressure-sensitive recording sheet was prepared as follows. That is, a self-coloring pressure-sensitive recording layer having the above composition was applied to a high-quality paper having a basis weight of 92 g / m ^{2 so} that the coating amount was 8 g / m ² , thereby obtaining a self-coloring pressure-sensitive recording sheet.

Example 1 A low-density polyethylene (density: 0.9) was formed on a recording surface of a self-coloring pressure-sensitive recording sheet prepared in a preliminary operation by using a melt extrusion die as a polyolefin resin laminate layer.
18 g / cc) was laminated to 8 g / m ² . An ultraviolet-curable silicone resin (KNS5300, manufactured by Shin-Etsu Chemical Co., Ltd.) was applied thereon with a reverse roll coater to a concentration of 0.6 g / m ² , and an ultraviolet irradiation device (Rapid, manufactured by USHIO INC.) Cure). Further, 10 g / adhesive resin IRR84 (containing 5% by weight of Irgacure 651 as a reaction initiator) from Radcure Specialties Co., Ltd. as an adhesive.
applying the offset gravure coater so that m ^2, was cured by ultraviolet irradiation, opaque as the cover sheet, superposing a cast coated paper having a basis weight of 50 g / m ² The purpose of pressure-sensitive recording sheet having a printing portion I got

Example 2 On a recording surface of the self-coloring pressure-sensitive recording sheet prepared in the preliminary operation, a medium-density polyethylene (density: 0.9) was formed using a melt extrusion die as a polyolefin resin laminate layer.
28 g / cc) was laminated to 10 g / m ² . An electron beam-curable silicone resin (trade name: X-62-7192, manufactured by Shin-Etsu Chemical Co., Ltd.) was applied thereon with a reverse roll coater to a concentration of 0.6 g / m ² , and an electron beam irradiation device (Nissin) High voltage, Curetron)
And irradiated with an electron beam at an electron beam accelerating voltage of 200 kV and an absorbed dose of 3 Mrad to cure. Further, an adhesive (Toyo Ink, BPS8170) is further applied on the surface with a comma coater.
g / m < ² >, and dried, and superimposed on a high-quality paper of 40 g / m < ² > having a printed portion as an opaque covering sheet to obtain a target pressure-sensitive recording sheet.

Example 3 A medium-density polyethylene (density: 0.9) was formed on a recording surface of a self-coloring pressure-sensitive recording sheet prepared in the preliminary operation by using a melt extrusion die as a polyolefin resin laminate layer.
28g / cc) and polypropylene (density: 0.905g)
/ Cc) was laminated so as to be 10 g / m ² . A silicone resin emulsion (trade name: KM763, manufactured by Shin-Etsu Chemical Co., Ltd.) was applied thereon with a blade coater to a dry weight of 0.6 g / m ^2, and dried by heating. Basis weight 5 with printing part as opaque covering sheet
Using a coated paper of 0 g / m ² , an adhesive (manufactured by Konishi Co., Ltd., Bond CE560) was applied on the back surface at a dry weight of 10 g / m ^2.
m ² , dried and superimposed on the silicone resin layer to obtain the desired pressure-sensitive recording sheet.

Comparative Example 1 The self-coloring pressure-sensitive recording sheet obtained in the preliminary operation was used for evaluation without providing a silicone resin layer.

Comparative Example 2 A thermosetting silicone resin solution (trade name KL, manufactured by Shin-Etsu Chemical Co., Ltd.) was applied to the self-coloring pressure-sensitive recording sheet obtained by the preliminary operation.
-838) and a low-temperature curable platinum catalyst (CATPL-
8) 1% is mixed, and the solid content is 0.6 g with a gravure roll.
/ M ² and heat-cured with a hot air circulating dryer at 100 ° C. Further, an adhesive (BPS8170, manufactured by Toyo Ink Co., Ltd.) was further applied thereon with a comma coater at 10 g / m ^2.
Then, high-quality paper having a printing portion as an opaque cover sheet and a basis weight of 40 g / m ² was overlaid to obtain a target pressure-sensitive recording sheet.

Tests: Examples 1-3 and Comparative Examples 1-3
Of the pressure-sensitive recording sheet obtained in Example 2 were evaluated for color density, color developing speed, printability, friction resistance, oil resistance, and water resistance. Table 1 shows the results.

[Coloring Density] The coloring density of each pressure-sensitive recording sheet was determined by printing a fixed area on the opaque coated sheet with an impact printer, and then peeling off the opaque coated sheet to expose the color printing surface. Was measured with a Macbeth reflection densitometer. Based on the color density of the self-coloring type pressure-sensitive recording sheet prepared in the preliminary operation, relative values of 90% or more were excellent, relative values of 70% or more and less than 90% were inferior, and values of less than 70% were inferior.

[Friction Resistance] The rub resistance was determined by rubbing the opaque coated sheet surface of each pressure-sensitive recording sheet lightly with steel wool, peeling the opaque coated sheet, and determining the coloring of the recording surface. The case where there was no obstacle due to friction at all on the recording surface was excellent, the case where coloring due to a few lines of friction was recognized, and the case where there was an obstacle due to friction enough to hinder reading or the case where the record could not be read was inferior.

[Oil resistance and water resistance] Oil resistance and water resistance are measured by dropping one drop of xylene or water on the recording surface in a state where the opaque cover sheet of each pressure-sensitive recording sheet is peeled off. Judgment was made based on the time of seepage to the back side.

[Exposure] In the printability test, a record printed by a printer was evaluated as excellent when it could not be read as it was, and poor when it could be read.

[0050]

[Table 1]

Evaluation: The pressure-sensitive recording sheets obtained in Examples 1 to 3 were free from the occurrence of color fogging due to friction and water-resistant compared to the self-coloring pressure-sensitive recording sheet (Comparative Example 1). It was excellent in oil resistance, was comparable in color density to the self-coloring pressure-sensitive recording sheet, and was capable of concealing the content of pressure-sensitive recording by the opaque covering sheet. The opaque covering sheet had good peelability and could be used as a label if necessary.

On the other hand, when the polyolefin resin laminate layer obtained in Comparative Example 2 was not provided, there were problems such as impaired color development and poor printability. In the case of the self-coloring pressure-sensitive recording sheet having no opaque covering sheet (Comparative Example 1), it is obvious that not only are there problems in water resistance, oil resistance, and abrasion resistance, but there is no concealment of the recording. .

[0053]

According to the pressure-sensitive recording sheet of the present invention, the silicone resin provided on the recording surface does not seep into the pressure-sensitive recording layer due to the function of the polyolefin resin laminate layer, and has a surface releasability with a small amount of silicone resin. A high color density can be obtained while maintaining the color density. The silicone resin itself exhibits high water resistance, and the polyolefin resin laminate layer exhibits high oil resistance. Also, since release paper is unnecessary,
When used as a label, not only is there a cost advantage, but there is no need to discharge unnecessary release paper. Colors can be formed at a good recording density during pressure-sensitive recording, and the printed surface has excellent gloss, scratch resistance, and friction resistance. Can be handled without being exposed to the public,
The pressure-sensitive recorded information can be read by peeling off the opaque cover sheet as required. As described above, the present invention is of great industrial significance because it can be used in many applications such as continuous slips, pasted slips, correspondence such as labels and postcards, recording, and dust-free recording paper.

Claims (1)

(57) [Claims] 1. A pressure-sensitive recording layer, a polyolefin resin, in which microcapsules containing at least one of a color former and a developer are individually laminated or mixed on one surface of a support. Laminate layer, a polydialkylcyclohexane molecular main chain terminal or side chain of acryloyl group, methacryloyl group, or a silicone compound in which one or more functional groups of epoxy groups are introduced into a high energy ray composed of ultraviolet rays or electron beams. A pressure-sensitive recording sheet comprising: a silicone resin layer, an adhesive layer, and an opaque coating sheet cured by at least one kind.